Buggy code:
class Simulator { private static final String root = "pb" ; public static void main ( String [ ] args ) { int default_asteroids = 5 ; int random_asteroids = - 1 ; long time_limit = 365 * 1000 ; boolean gui = false ; boolean gui_fast_forward = false ; boolean gui_planets = true ; int gui_refresh_rate = 20 ; String state_file = null ; double min_orbit = 2.5E11 ; double max_orbit = 7.0E11 ; double min_mass = 0.8 * ( Orbit . M ) ; double max_mass = 1.2 * ( Orbit . M ) ; Point [ ] asteroid_position = null ; double [ ] asteroid_mass = null ; long init_timeout = 0 ; long play_timeout = 0 ; Class < Player > player = null ; String group = "g0" ; try { for ( int a = 0 ; a != ( args . length ) ; ++ a ) if ( ( args [ a ] . equals ( "-g" ) ) || ( args [ a ] . equals ( "--group" ) ) ) { if ( ( ++ a ) == ( args . length ) ) throw new IllegalArgumentException ( "Missing<seq2seq4repair_space>group<seq2seq4repair_space>name" ) ; <START_BUG> group = args [ ( ++ a ) ] ; <END_BUG> } else if ( ( args [ a ] . equals ( "-s" ) ) || ( args [ a ] . equals ( "--state" ) ) ) { if ( ( ++ a ) == ( args . length ) ) throw new IllegalArgumentException ( "Missing<seq2seq4repair_space>state<seq2seq4repair_space>file" ) ; state_file = args [ a ] ; } else if ( ( args [ a ] . equals ( "-a" ) ) || ( args [ a ] . equals ( "--asteroids" ) ) ) { if ( ( ++ a ) == ( args . length ) ) throw new IllegalArgumentException ( "Missing<seq2seq4repair_space>state<seq2seq4repair_space>file" ) ; random_asteroids = Integer . parseInt ( args [ a ] ) ; if ( random_asteroids < 2 ) throw new IllegalArgumentException ( "Cannot<seq2seq4repair_space>have<seq2seq4repair_space>less<seq2seq4repair_space>than<seq2seq4repair_space>2<seq2seq4repair_space>asteroids" ) ; } else if ( ( args [ a ] . equals ( "-t" ) ) || ( args [ a ] . equals ( "--time" ) ) ) { if ( ( ++ a ) == ( args . length ) ) throw new IllegalArgumentException ( "Missing<seq2seq4repair_space>time<seq2seq4repair_space>limit<seq2seq4repair_space>parameter" ) ; time_limit = Long . parseLong ( args [ a ] ) ; if ( time_limit < 0 ) throw new IllegalArgumentException ( "Invalid<seq2seq4repair_space>time<seq2seq4repair_space>limit" ) ; } else if ( args [ a ] . equals ( "--gui-fps" ) ) { if ( ( ++ a ) == ( args . length ) ) throw new IllegalArgumentException ( "Missing<seq2seq4repair_space>the<seq2seq4repair_space>FPS<seq2seq4repair_space>parameter" ) ; double fps = Double . parseDouble ( args [ a ] ) ; if ( fps < 0.0 ) throw new IllegalArgumentException ( "Invalid<seq2seq4repair_space>FPS<seq2seq4repair_space>parameter" ) ; if ( fps == 0.0 ) gui_refresh_rate = - 1 ; else gui_refresh_rate = ( ( int ) ( Math . round ( ( 1000 // fps ) ) ) ) ; gui = true ; } else if ( args [ a ] . equals ( "--init-timeout" ) ) { if ( ( ++ a ) == ( args . length ) ) throw new IllegalArgumentException ( "Missing<seq2seq4repair_space>the<seq2seq4repair_space>init()<seq2seq4repair_space>timeout<seq2seq4repair_space>parameter" ) ; init_timeout = Long . parseLong ( args [ a ] ) ; if ( init_timeout < 0 ) init_timeout = 0 ; } else if ( args [ a ] . equals ( "--play-timeout" ) ) { if ( ( ++ a ) == ( args . length ) ) throw new IllegalArgumentException ( "Missing<seq2seq4repair_space>the<seq2seq4repair_space>play()<seq2seq4repair_space>timeout<seq2seq4repair_space>parameter" ) ; play_timeout = Long . parseLong ( args [ a ] ) ; if ( play_timeout < 0 ) play_timeout = 0 ; } else if ( args [ a ] . equals ( "--orbit-range" ) ) { if ( ( a + 2 ) >= ( args . length ) ) throw new IllegalArgumentException ( "Missing<seq2seq4repair_space>orbit<seq2seq4repair_space>range<seq2seq4repair_space>parameters" ) ; min_orbit = ( Integer . parseInt ( args [ ( ++ a ) ] ) ) * 1.0E9 ; max_orbit = ( Integer . parseInt ( args [ ( ++ a ) ] ) ) * 1.0E9 ; if ( ( ( min_orbit <= 0 ) || ( max_orbit <= 0 ) ) || ( min_orbit > max_orbit ) ) throw new IllegalArgumentException ( "Invalid<seq2seq4repair_space>orbit<seq2seq4repair_space>range<seq2seq4repair_space>parameters" ) ; } else if ( args [ a ] . equals ( "--mass-range" ) ) { if ( ( a + 2 ) >= ( args . length ) ) throw new IllegalArgumentException ( "Missing<seq2seq4repair_space>orbit<seq2seq4repair_space>range<seq2seq4repair_space>parameters" ) ; min_mass = ( Double . parseDouble ( args [ ( ++ a ) ] ) ) * ( Orbit . M ) ; max_mass = ( Double . parseDouble ( args [ ( ++ a ) ] ) ) * ( Orbit . M ) ; if ( ( ( min_mass <= 0 ) || ( max_mass <= 0 ) ) || ( min_mass > max_mass ) ) throw new IllegalArgumentException ( "Invalid<seq2seq4repair_space>orbit<seq2seq4repair_space>range" ) ; } else if ( args [ a ] . equals ( "--density" ) ) { if ( ( ++ a ) == ( args . length ) ) throw new IllegalArgumentException ( "Missing<seq2seq4repair_space>density<seq2seq4repair_space>parameter" ) ; Asteroid . density *= Double . parseDouble ( args [ a ] ) ; if ( ( Asteroid . density ) <= 0.0 ) throw new IllegalArgumentException ( "Invalid<seq2seq4repair_space>density<seq2seq4repair_space>parameter" ) ; } else if ( args [ a ] . equals ( "--gui" ) ) { gui = true ; } else if ( args [ a ] . equals ( "--gui-no-planets" ) ) { gui_planets = false ; gui = true ; } else if ( args [ a ] . equals ( "--gui-fast-forward" ) ) { gui_fast_forward = true ; gui = true ; } else throw new IllegalArgumentException ( ( "Unknown<seq2seq4repair_space>argument:<seq2seq4repair_space>" + ( args [ a ] ) ) ) ; player = Simulator . load ( group ) ;

Fix:
group = args [ a ] ;